Not sure what you are talking about. It is not really up to you to decide how much a flight 'deserves' to be..
Results from https://www.ExpertFlyer.com
Code:
Departing ATH on 05/12/22 for CDG
Flying A3
Purchasing at ATH
Viewing in currency EUR
Searching in Business cabin
Validated Results
Fare Basis Airline Booking Trip Type Fare Cabin Effective Expiration Min/Max Advanced
Class Date Date Stay Purchase Req
ALCCFLW A3 A One-Way 158.00 (EUR) B 01/10/23 30/06/23
ZLCCFLW A3 Z One-Way 217.00 (EUR) B 01/10/23 30/06/23
ZNLHCC A3 Z One-Way 251.00 (EUR) B
DLCCFLW A3 D One-Way 279.00 (EUR) B 01/10/23 30/06/23
DNLHCC A3 D One-Way 331.00 (EUR) B
CNLHCC A3 C One-Way 466.00 (EUR) B
CLCCFLW A3 C One-Way 605.00 (EUR) B 01/10/23 30/06/23
There are plenty of fares between ATH and CDG, in business, that are reasonably priced. Likely you are talking about an availability issue, i.e. only C-class is still available. That happens when the flight is almost full or close to departure. Very common with every airline. If you want lower prices - book to fly off-peak and plenty of time ahead. When you find A-class you fare is going to be around ~200 euro all-in.